BPF support for global data

This series is a major rework of previously submitted libbpf
patches [0] in order to add global data support for BPF. The
kernel has been extended to add proper infrastructure that allows
for full .bss/.data/.rodata sections on BPF loader side based
upon feedback from LPC discussions [1]. Latter support is then
also added into libbpf in this series which allows for more
natural C-like programming of BPF programs. For more information
on loader, please refer to 'bpf, libbpf: support global data/bss/
rodata sections' patch in this series. Joint work with Joe Stringer.

Thanks a lot!

  v1 -> v2:
    - Instead of 32-bit static data, implement full global
      data support.

  [0] https://patchwork.ozlabs.org/cover/1040290/
  [1] http://vger.kernel.org/lpc-bpf2018.html#session-3

Daniel Borkmann (5):
  bpf: implement lookup-free direct value access
  bpf: add program side {rd,wr}only support
  bpf, obj: allow . char as part of the name
  bpf, libbpf: support global data/bss/rodata sections
  bpf, selftest: test {rd,wr}only flags and direct value access

Joe Stringer (2):
  bpf, libbpf: refactor relocation handling
  bpf, selftest: test global data/bss/rodata sections

 include/linux/bpf.h                           |  24 ++
 include/linux/bpf_verifier.h                  |   4 +
 include/uapi/linux/bpf.h                      |  16 +-
 kernel/bpf/arraymap.c                         |  35 +-
 kernel/bpf/core.c                             |   3 +-
 kernel/bpf/disasm.c                           |   5 +-
 kernel/bpf/hashtab.c                          |   2 +-
 kernel/bpf/local_storage.c                    |   2 +-
 kernel/bpf/lpm_trie.c                         |   2 +-
 kernel/bpf/queue_stack_maps.c                 |   3 +-
 kernel/bpf/syscall.c                          |  35 +-
 kernel/bpf/verifier.c                         | 103 ++++--
 tools/bpf/bpftool/xlated_dumper.c             |   3 +
 tools/include/linux/filter.h                  |  19 +-
 tools/include/uapi/linux/bpf.h                |  16 +-
 tools/lib/bpf/libbpf.c                        | 321 ++++++++++++++----
 tools/testing/selftests/bpf/bpf_helpers.h     |   2 +-
 .../selftests/bpf/progs/test_global_data.c    |  61 ++++
 tools/testing/selftests/bpf/test_progs.c      |  50 +++
 tools/testing/selftests/bpf/test_verifier.c   |  40 ++-
 .../selftests/bpf/verifier/array_access.c     | 159 +++++++++
 .../bpf/verifier/direct_value_access.c        | 170 ++++++++++
 22 files changed, 955 insertions(+), 120 deletions(-)
 create mode 100644 tools/testing/selftests/bpf/progs/test_global_data.c
 create mode 100644 tools/testing/selftests/bpf/verifier/direct_value_access.c

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2.17.1